It Should be a Sin
by Icy Amour
Summary: Angel/Demon AU! PruCan. Yaoi, consider yourself warned! Gilbert is a guardian angel who enjoys flying more than anything in the world. One day while watching over his charge he meets a mortal, Matthew, who can see him, and they form a bond. As they grow closer Gil wonders if Matt is worth falling for because there is more to him than meets the eye.


**AN: Hi all I'm back with a PruCan one shot for my wonderful fan/friend Skouratapramata. Her prompt was 'Flying'. Now Mattie is a demon so keep that in mind as you read and the same goes for Gil as an angel. I hope everyone enjoys (especially you Skoura).**

 **I just own the story!**

* * *

'It should be a sin to feel this awesome!' Gilbert thought joyously as he swooped and glided through the blue skies of the mortal world. His ivory wings glistened in the summer sunshine. His heavenly glow was an exquisite silver shimmer around his pale frame clothed in a simple toga and leather sandals that laced to just below his knee. The glow of his halo made his exceptionally pale blonde hair shine and his ruby eyes glimmered.

Flying had to be the single best thing about being an angel. Well other than helping people, but that was his job. Who really loved everything about their job anyway?

Tucking his wings in close to his body the angel shifted into a nose dive and careened headlong toward the city below him. While he could have spent hours even days just soaring through the sky he did have work to do. A certain blue eyed, blonde needed a quick visit from his guardian angel.

As the world grew closer a manic smile spread across his face and adrenaline coursed through his veins.

"Just a little more," he murmured to himself as his descent was becoming dangerously close to becoming a crash. Just as it seemed that Gilbert was going to become a smear on the concrete he unfurled his wings so they acted as a sort of parachute drastically slowing him down. His sandaled feet alighted on the sidewalk gently as if he had been a leaf casually falling from a tree in autumn.

With determined steps he began walking down the busy sidewalk. He knew Ludwig's routine down to the second and right about now the stoic man would be on his way to the little cafe just a block from his apartment.

A fond grin crept onto the albino's face as he spotted his charge walking just ahead of him. Ludwig was a tall man with broad shoulders who hailed originally from Germany. Gilbert had been looking after the man since he was a young boy. He'd come to look upon the German has a younger brother.

Which is why he now gave an exasperated sigh as he watched the tall blonde hesitate just outside the door of the cafe. The reason that Ludwig came to this particular cafe wasn't because the coffee was good. No, he came here because the big lummox had an undying crush on the cafe co-owner, Feliciana Vargas.

For six months the silvery angel had watched in anguished dismay as his charge came to the cafe, ordered a small latte, and then just left. To say the blue eyed male was hopeless when it came to romance would be an understatement. The German had to be the most awkward dork on the planet. Oh, he had tried once to ask the beautiful Italian girl out on a date. Sadly, he had been so nervous he could only speak in German and spilt his coffee all over his shirt front. It had been so painful for Gilbert to watch it had nearly killed him. Well figuratively.

Today though that was all going to change. Moving swiftly the albino slipped in behind the blonde and stayed close to his side as they approached the counter. A warm smile and bright amber eyes shined as the barista noticed them.

"Ciao, Luddy!" the auburn haired woman chirped merrily.

"Hallo, Feli. Just the usual," Ludwig returned the greeting with a slight blush on his cheeks.

"Mein Gott, Lud. You're freaking adorable, but quit blushing like a fourteen year old girl," the vermilion eyed angel groused, but his words fell on deaf ears. One of the crappy things about being an angel was that ninety-nine percent of the living could neither see nor hear you. It was at the same time very helpful, but also very frustrating.

"Right away, tesorino," Feliciana said with a wink as she rang up the order.

The cobalt eyed man's blush darkened at the endearment as he reached into his back pocket for his wallet.

"All right, it's show time," Gilbert said merrily with a mischievous smirk. He began rubbing his hands together vigorously and they quickly became enveloped in silverlight.

As Ludwig slipped his credit card from its slot in the brown leather billfold embossed with the German flag the angel's right hand came up behind his head.

"Ein," the silvery blonde murmured as Feliciana held her hand out expectantly.

"Zwei," the stoic blonde extended his arm with the card at the ready.

"Drei!" Gilbert then proceeded to smack his charge squarely on the back of his head sending a rush of magic into him just as his hand grazed the pretty Italian girl's own hand. A burst of confidence seized the blonde male. Bolstered by this sudden strengthening in character he dropped his card on the counter and grasped the auburn haired girl's hand gently.

"Feli, I've been wanting to ask you something for some time now, but have been too scared until now," Ludwig said with conviction as his cobalt eyes longingly bore into surprised honey ones. "Feliciana, could I take you out for dinner sometime?"

Feliciana gasped in shock before the biggest smile anyone had ever seen broke out on her spritely face.

"Of course, Luddy! I've been dying for you to ask me since that first day you came into the cafe!" the little barista exclaimed joyously as she pulled away from the large man and dashed around the counter. Before the stoic man had time to react he found himself enveloped in a tight hug by the petite Italian woman. A scarlet blush quickly bloomed across the German's cheeks as the angelic magic slowly seeped away and made Gilbert chuckle in satisfaction.

"And my job is done here for today," the angel mused aloud as he turned and made his way out of the small cafe as another couple entered.

The albino whistled merrily as he strolled along the sidewalk. Having met his 'one good deed for Lud a day' quota the red eyed man felt he had earned some extra flying time before having to return to heaven.

Just as Gilbert stopped at the entrance of an alley and prepared to launch skyward a sudden scream caught his attention.

Turning quickly toward the sound, ruby eyes widened in shock at the scene he found. Two filthy, sallow looking demons had a mortal cornered at the back of the alley.

Righteous fury filled the angel to bursting as he charged into the alley without a second thought.

Hearing the approach of another being the demons turned and their sunken gray eyes widened in shock. They had no time to react before Gilbert was upon them.

As he closed in on the vile beasts he called upon his magic to manifest a heavenly sword into his hand. Moving with grace and agility the pale man swung the blade in a large sweeping arch before him. The magic construct hissed as its divine surface cut and seared through first one then the other demon's torso killing them both instantly.

The two underworlders cried out in agonizing pain before their forms morphed into a tarry substance and splattered onto the ground.

The silvery angel smirked victoriously and willed away his weapon. As his holy fury ebbed away Gilbert was able to focus on the human before him. He was a slender, tall young man with shoulder length wavy blonde hair. A single curl hung separately from the wavy locks and the angel grinned at how cute that was. His features were strong, but held a certain softness to them. He was dressed simply in a red hoodie, blue jeans, and red converses. The young man's glasses were askew, that didn't matter since he had his eyes closed tightly. He panted heavily in fear and his body shook terribly.

Wishing to help relax the poor thing the pale male reached out to lend some soothing heavenly magic. He stopped though when suddenly the other man's eyes flew open and stared warily at him with irises the color of amethysts.

"P-please don't h-hurt me," the slender blonde stammered out as he tried vainly to press back into the wall he was against.

For a moment the red eyed man was completely frozen in shock. It had been so long since a mortal had been able to see and speak with him that the whole situation had taken him by complete surprise. That and the mortal had to be the most gorgeous thing he had ever seen. Shaking himself out of his stupor the silver haired angel offered a gentle smile to the man before him.

"I'm not going to hurt you. If you hadn't noticed I'm an angel. Harming humans kind of goes against my nature," Gilbert explained with a mirthful chuckle.

"An angel?" the slender male queried his brow furrowed slightly and his posture relaxed ever so marginally. "I've never seen an angel before. I've only ever seen demons,"

"Only ever...How long have you been able to see demons and angels?" the silver haired man asked curiously.

"For as long as I can remember, " the lemon blonde responded and relaxed a little more. "What's your name?"

The angel blinked at the human as he was taken by surprise at the sudden question before beaming proudly.

"I'm the awACK!" the albino cried out in pain and his grin became a grimace as the base of his wings burned intensely.

"Are you okay?" the blonde man asked worriedly and took a tentative step closer to the other man.

As the pain faded the silver haired man shot a reassuring smile at his companion.

"I'm fine. I just forget myself sometimes and the divine sends me a little reminder," Gilbert responded as he gingerly stretched his wings.

"Reminder?" the violet eyed male queried as his worried brow drew together in confusion.

"Yeah. When an angel says or does something that could be considered sinful the base of their wings will burn. It's the hire ups way of keeping us from falling," the pale angel explained.

"But why make your wings burn? Isn't there a...gentler way to warn you?" the blonde mortal questioned.

"It's the most effective way, because if you fall then you lose your ability to fly," the pale haired male stated as his features became grave.

"That's horrible," the slender man said casting his beautiful eyes downward.

"It's fine," the red eyed man said with a pang of remorse for bringing down the mood. "Anyway, back to your original question. My name is Gilbert. What's yours?"

"Matthew," the blonde responded as he looked back up at the other man and gave him a small smile.

"Matthew. That's a nice name. It suits you," Gilbert said as he felt his heart flutter in his chest at the sight of the adorable smile.

"Thank you," Matthew said as he absently reached up and tucked his hair behind his ear.

'SO CUTE!' the albino internally squealed. He opened his mouth to respond, but stopped when the call of a trumpet caught his attention. It was the call for the angels to return home.

"Darn it," the angel groused as he turned an apologetic look on his new friend. "Their calling us home,"

The lemon blonde's face fell in disappointment and again his gaze fell to the ground.

"Will I be able to see you again?" he said so softly it was nearly inaudible.

Gilbert knew he should say no. It wasn't wise to get attached to a mortal. Especially one that was not a charge, but there was something about Matthew. He found himself despairing at the thought of never seeing this special human again.

"I'm at the cafe around the corner nearly everyday with my charge at this time. You can meet me there,"

Matthew's head shot up and he had the biggest, brightest smile on his handsome face.

"All right then. I'll see you tomorrow," he said with uncontained joy and made the angel's heart flutter again.

"It's a date," the vermilion eyed man said with a wide grin of his own before turning and launching into the air. He'd never been so excited to go to work.

* * *

Matthew watched until the angel disappeared from sight before letting his smile form into a smirk. He then raised his right hand palm out and it became engulfed in purple flame.

"Door," he commanded and the area just before his palm distorted. The air split in two and opened to form a wide arch. The wavy haired blonde then stepped forward into the opening and as he did his features began to change.

His hoodie shifted into a loose long sleeved button up and jeans became form fitting leather. Red converses morphed into short black boots. His blonde hair became white with purple low lights shimmering in the light and a pair of curled horns sprouted from either side of his head. A thin, spade tipped tail descended from the base of his spine and large, black bat wings sprouted from his shoulder blades. Heaven's little reminder of what they had lost.

The door he had opened led into a wide, cavernous hall that seemed to be crafted from volcanic rock. Numerous wall sconces lined the walls and their torchlight filled the space.

Matthew walked casually down the hall until he reached a pair of obsidian black doors. With a flick of his wrist the doors opened to reveal a moderately sized bed chamber.

The pale haired man ambled into the room and fell face first onto the bed with a tired sigh.

"Did you have a nice trip brother dear?" a familiar voice queried.

The violet eyed demon exhaled an irritated sigh and pushed up onto his forearms.

"Why are you in my room, Alfred?" the slender male asked as he turned an aggravated glare on the pair occupying his arm chair on the other side of the room. Matthew's fraternal twin brother, Alfred, was seated in the black velvet chair looking rather bored with his head propped up against his fist. His other arm was wrapped around the waist of the smaller, red haired man perched on his lap. The other male was rather intently nuzzling and licking at the larger man's neck with a slender hand carding into his black hair.

"Waiting for you to return of course. How did things go?" Alfred asked casually with an eager glint in his glowing blue eyes.

"Splendidly. I think I have found our pride," the amethyst eyed demon said with a triumphant grin as he pushed himself up into a sitting position.

"Excellent," Alfred said turning his head and placing a kiss on his companion's forehead. "Did you hear that, Arthur?"

"Mmm...Yes, my love," greens eyes opened and turned up to look hungrily at the other man. "Soon you'll have enough power to bring your wrath to Heaven's gates,"

Pressing upward the smaller man pressed his lips firmly to his lover's own as he shifted to straddle the man's lap.

"Ahem, could you maybe not defile my armchair," Matthew interjected before the other two demons could deepen their make out session. Glowing viridian eyes turned to glower at him.

"Apologies, Matthew. I'm just a bit hungry," Arthur groused as he again shifted to sit upon Alfred's lap.

"Be nice, babe. I'll take care of all your lusty little needs in a bit," Alfred soothed as he placed a kiss on his lover's cheek. "Did you have anything else to report, Mattie?"

Cerulean eyes shifted to settle on the pale haired demon.

"Yes. It seems that Heaven has implemented a fail safe to keep angels from falling,"

"Oh, and what may that be?" a deep frown marred Alfred's features.

"When angels do or say something sinful the bases of their wings will burn. This may pose a problem," Matthew said worrying his lower lip.

"Oh, is that all?" Alfred said with a snort. Iridescent purple eyes glowered at him angrily.

"This is serious, Al. Pain is a pretty good deterrent,"

"True, but if you associate pain with pleasure then the game changes. This shouldn't be any harder than getting a prudish archangel to fall," the blue eyed demon said as he turned a loving smile on Arthur. "But I understand that not everyone can be as awesome as me,"

A flash of anger with a hint of envy shone in Matthew's eyes as he glared at his brother. A triumphant smile stretched across Alfred's face as he rose to his feet and held Arthur in his arms bridal style.

"Well I'll leave you to it, brother dear," the dark haired demon said as he began to stride from the room. "Now where does my little lust demon want to have his meal? Franny's room?"

"No, that gluttonous frog is probably in there. The greedy Spaniard probably has that lazy Italian in his room. How about the kitchen? I can have something sweet with my salty treat," Arthur purred as the pair disappeared from sight.

With a harsh flick of his wrist Matthew made his doors slam closed angrily and fell back on his bed with a growl.

"Just you wait, Al. I'll show you that you aren't the only one who can make angels fall,"

* * *

Several weeks had passed since Gilbert had met Matthew and the angel was on the figurative cloud nine. Things had been going so well in Ludwig's life that he very rarely needed the angel around. This was good for the albino, because it meant he could spend more time with Matthew.

He found himself thinking more and more about the blonde mortal as the days passed. Matthew was unlike anyone he had ever met before; Angel or otherwise. He was sweet and kind not to mention drop dead gorgeous. He listened to everything Gilbert had to say and never belittled him like some of the angels in Heaven did. He made the silvery angel feel special. More like awesome really.

He was finding his wings burning more often when he thought of the violet eyed man, but he was actually coming to enjoy the pain. The burning sensation was nothing compared to not getting to think of or touch the man he had come to care so very much about.

Touching Matthew was on the same level as flying to Gilbert. They had only touched hands a few times but each time was electrifying. The blonde's skin was so soft and it made Gilbert's own skin tingle. The red eyed angel couldn't get enough of the little touches and found himself wondering if his lips were just as soft.

"I wonder what they taste like," he softly mused aloud as he thought of kissing those lips and the burning sensation started in his wings as he lie on a cloud just before his descent to Earth for the day.

Just then someone cleared their throat behind the daydreaming angel causing him to nearly topple off of his cloud in shock.

Once he was righted, Gilbert looked up with a glare at the brunette woman who stood behind him.

"Geez, Liz, are you trying to kill me?" he groused at his friend slash superior.

"Sorry about that, Gil," Elizaveta apologized with a good natured chuckle.

"So what's up? Rod send you to lecture me, again?" he queried as he rose to his feet.

"I have some bad news," the female angel said her pretty lips turning down into a frown and the albino quirked a brow at her. "Gil you're being reassigned,"

"W-what?!" Gilbert stammered out as he felt a horrid coldness begin to fill his body.

"The higher ups feel you have gotten to close to your charge and it seems to be tarnishing you," the brunette explained as she cursed her superiors for giving this task to her. She did not want to hurt her friend like this.

"I've been with Lud since he was a kid. I know him better than his own mother," the red eyed angel ranted as he struggled to wrap his mind around the situation.

"And that is the problem, Gil," Liz felt her heart breaking for her friend. "Your new assignment starts tomorrow. You have until the trumpet to finish up any business you had with Ludwig,"

With that the brunette angel flew away her green eyes clouded with tears.

Gilbert stood frozen in place to the cloud he stood on. They were reassigning him. Those lousy archangels were sending him away for doing his job too well. What kind of backwards logic was that?

The archangels had implemented some pretty strict rules and 'reminders' since one of their own had fallen, but this was ridiculous. If they reassigned him then he'd never see Ludwig again. Who was going to help Lud when he was being way too dorky around Feli? Who was going to give the big galoot the kick in the pants he need to propose or give him that calming serenity he needed when they had kids? Most importantly would he ever be able to see Matthew again?

That simple thought alone set Gilbert into motion. With a running start the angel threw himself off of his cloud and performed a perfect swan dive. His heart hammered in his chest, not from a rush of adrenaline, but from the icy fear of never seeing his beloved mortal again.

 _Beloved?!_ In that moment the albino realized that the burning he had been feeling for the little blonde was simply that: Love! Yes, he loved Matthew and by his holy sword he would find some way for them to be together.

As the Earth grew dangerously close Gilbert unfurled his wings and alighted softly on the pavement in front of the little cafe. As soon as his feet were firmly on the ground the angel looked about desperately for his mortal sweetheart.

A flash of lemon blonde hair caught his eye and he was off down the street turning into the alley where the pair had first met. There in the middle of the alley stood the person he had been looking for.

"Matthew," he said just barely above a whisper as he raced forward and took the slender male into his arms.

"Gi-Gilbert?!" Matthew sputtered out in surprise as he returned the other man's embrace and felt him shaking. "What's wrong, Gil?"

"Oh, Mattie. They are reassigning me," he said and could feel Matthew stiffen in his arms.

"What?" the blonde queried as he pressed on the angel's shoulders forcing him back so that misty amethyst could meet distraught vermilion.

"Don't worry I'll figure out some way to stop this," Gilbert said with reassurance as his hand came up to gently cradle the other man's cheek. "I won't be separated from you,"

Matthew smiled sweetly up at the angel and nuzzled into the palm of his hand.

"Don't worry, dearest. You won't have to be,"

With an amazing amount of speed the lemon blonde shot forward and his hands fisted into the toga Gilbert wore as he crashed their lips together. Pleasure like he had never felt before surged through the albino and he instantly returned the kiss as his arms wound around Matt's slender waist.

Matthew's tongue slipped out to tease at Gilbert's bottom lip and he happily complied by opening his mouth. The smaller male's pink appendage boldly ventured into the other man's mouth only to be forced back and quickly dominated. The angel ravaged the mortal's mouth exploring every crevice.

Needing air Matthew pulled back and panted out a single word that Gilbert did not hear so lost in the moment was he. With minimal effort the slender male managed to walk the pair backward. The angel thought he would find himself pressed against a wall, but gasped in surprise when the backs of his knees instead hit something soft. The kissing duo tumbled onto the magically appearing mattress, but did not break their embrace.

In the back of Gilbert's mind little, red warning flags were flying everywhere and he knew he should stop all of this immediately. Yet, he could not bring himself to care as his hands roamed over the compliant body atop him. His wings felt as if they had been set ablaze, but so did the rest of his body as Matthew's slender hands explored him.

As those devious hands traveled further south they came to the hem of the angel's toga and tugged it upward.

"My, my, so it's true. Angels don't wear anything beneath their togas," Matthew purred as he pulled back from the kiss with a smirk. "That makes things all the easier for me,"

With that the periwinkle eyed male sat up and looked at his blushing soon to be lover. Oh, he was so going to enjoy this. With a snap of his fingers all his clothing dissolved away leaving him bare.

Again in the back of Gilbert's mind he knew that something very, very wrong was happening, but with his eyes taking in the delectable sight of a naked Matthew before him he could not bring himself to care.

"Like what you see, sweetie?" Matthew asked as he brought both hands up and then ran them down his lean frame.

"Yes," the albino rasped and then swallowed thickly.

"You're going to love this next part then," the purple eyed man said with a little giggle as he pressed up onto his knees. With another snap a little glass vial appeared in his hand and he quick uncorked it. Tipping it over a thick, clear liquid coated his hand. Once the vial was empty he tossed it aside and rubbed his hands together warming the substance.

"Gilbert, what would you do to keep me by your side?" Matthew asked as he slid his hand behind him to grasp the angel's fully erect cock. Gilbert gasped and his hands fisted into the sheets covering the bed.

"Any-anything," he panted as a new wave of pleasure seized him.

"Really?" the wavy haired blonde said with a devilish smirk. "Would you fall for me?"

This made Gilbert pause. If he fell then he would never fly again, but then he would never have to be separated from Matthew. To him the choice was clear.

"Yes," he said with conviction and triumph flashed in those purple eyes he loved so dearly.

"I thought you might say that," Matthew said as he pressed the head of the angel's dick to his previously prepared entrance and slowly sank down upon it. He moaned lecherously and watched through half lidded eyes as an angel fell before him.

Searing pain the likes of which he had never felt before coursed through the albino with every inch the other man took into him. The pain was concentrated at the base of his spine, just above his forehead, and his wings. He felt as if he was burning from the inside. The pain intensified as a pointed tail burst from his back and a pair of long slender horns curved back along his skull. The feathers of his wings felt as if they were being ripped out one by one. As the pristine white down dissolved away he was left with a pair of black, leathery bat wings.

Just when Gilbert thought he was surely going to die the pain began to ebb away and was being replaced by a euphoric pleasure like he had never felt before.

Matthew rose and fell above him as he rode the angel's cock. Erotic mewls and groans filled the air as the slender male worked to bring release.

Slowly, the silvery haired male lifted trembling hands to rest on his lover's hips to help guide him. An exceptionally pleasing coil of warmth was building in his belly.

Glowing violet eyes looked down tenderly at the man beneath him.

"Just when...I thought...you...couldn't get...more handsome…" Matthew panted as his eyes rolled back in his head. He had found his sweet spot and now bucked his hips in a way that hit it with every erratic thrust downward.

Wishing to speed them along to the pleasurable abyss, Gilbert began lifting his hips to match Matthew's thrusts thusly putting more pressure onto the demon's abused prostate.

A few thrusts later and the lemon blonde threw his head back with an ecstatic scream as bands of cum spilled out across the fallen angels stomach. Having lost his concentration the demon could no longer maintain his human form and his features changed to that of his true form.

As the walls of Matthew's ass clenched tightly around his throbbing cock Gilbert thrust up into that glorious warm, tightness until he too climaxed.

As he came down from his high, Matthew collapsed atop his lover and placed a kiss to his heaving chest. His now freed tail flicked about languidly and his wings lay slack on either side of him.

"Was that good for you, my proud fallen angel?" the demon asked coyly as he lazily traced unintelligible symbols onto the other man's body. Gilbert smirked before placing a kiss atop Matthew's head and embraced him.

"It should be a sin to feel this good,"

* * *

 **AN: And that's that! I hope you all enjoyed and will keep an eye out for my future one shots coming up. Until next time.**

 **In case you were wondering my seven sins demons are as listed:**

 **Wrath-Alfred, Lust-Arthur, Envy-Matthew, Pride-Gilbert, Gluttony-Francis, Sloth-Lovino, Greed-Antonio. I may someday come back and do more with this AU, but don't hold your breath.**


End file.
